The potential for the QTC material to transition from an insulator to a conductor (i.e. change its electrical property) is influenced by how much deformation the material is experiencing as a result of the applied mechanical pressure.
QTC can be used to produce low profile, low cost, pressure activated switches or sensors that display variable resistance with applied force and return to a quiescent state when the force is removed. The difference between a QTC switch and a QTC sensor is arguably only the speed and amount of physical input required to achieve the required switching point or resistance range.
